The rise of the Internet has rapidly transformed the manner in which electronic communications take place. Today, prior-generation switched telephone communications arrangements are rapidly being replaced with Internet Protocol (IP) based communications networks. IP communications networks can provide flexibility in facilitating the transmission of voice, data, video, and other information at great speeds.
In many cases, the IP communications networks comprise cable television networks that are used to transmit information between a service provider and a plurality of subscriber premises, typically over fiber optic and/or coaxial cables. The service provider may offer, among other things, cable television, broadband Internet and Voice-over-Internet Protocol (“VoIP”) digital telephone service to subscribers within a particular geographic area. The service provider transmits “forward path” or “downstream” signals from the headend facilities of the cable television network to the subscriber premises and “reverse path” or “upstream” signals may also be transmitted from the individual subscriber premises back to the headend facilities. In the United States, the forward path signals are typically transmitted in the 54-1002 MHz frequency band, and may include, for example, different tiers of cable television channels, movies on demand, digital telephone and/or Internet service, and other broadcast or point-to-point offerings. The reverse path signals are typically transmitted in the 5-42 MHz frequency band and may include, for example, signals associated with digital telephone and/or Internet service and ordering commands (i.e., for movies-on-demand and other services).
Significant attenuation may occur as signals are passed through the cable television network, and hence the power level of the forward path RF signals that are received at the subscriber premises may be on the order of 0-5 dBmV/channel. Such received signal levels may be insufficient to support the various services at an acceptable quality of service level. Accordingly, RF signal amplifiers may be provided at or near individual subscriber premises that are used to amplify the forward path RF signals to a more useful level. These RF signal amplifiers may also be configured to amplify the reverse path RF signals that are transmitted from the subscriber premises to the headend facilities of the cable television network. Typically, each signal amplifier will include a power divider network that divides the forward path signal and distributes it to multiple RF output ports, each of which may be connected to a respective one of a plurality of wall outlets throughout the subscriber premises. The power divider network may also combine any reverse path signals received from the wall outlets for transmission back to the headend facilities.
Unfortunately, RF signal amplifiers are active devices that require electrical power for proper operation. Accordingly, if electrical power to an RF signal amplifier is interrupted, some or all of the communications between the service provider and the subscriber premises may be lost. Although such interruptions may be tolerated in relation to certain non-essential services, interruptions to other services may be unacceptable. For example, subscribers relying on IP-based emergency communications (i.e., 911 service) can be left without such services during power interruptions. Interruption of 911 service is generally considered to be unacceptable. In order to remedy this problem, various signal amplifiers have been proposed that have both an active (amplified) communications path and a separate passive communications path. The VoIP telephone service may be provided over the passive communications path which will ensure that 911 telephone service will be supported even during power outages.
Another recent trend is to use the coaxial cables that are installed throughout most homes, apartments and other subscriber premises as a network that may be used to transmit signals from a device that is connected to a first wall outlet in a premises to other wall outlets. An industry alliance known as the Multi-media Over Coax Alliance (“MoCA”) has developed standards which specify frequency bands, interfaces and other parameters that will allow equipment from different standards-compliant vendors to be used to distribute multi-media content over in-premises coaxial cable networks. These standards specify that such “MoCA” content is transmitted over the in-premises coaxial cable networks in the 850 MHz to 1675 MHz frequency band, although many service providers only distribute MoCA content within a narrower frequency band that is above the cable television band, such as, for example, the 1150 MHz to 1550 MHz frequency band. Examples of MoCA content that may be distributed over an in-premises coaxial cable network are digital television, video-on-demand programming and digitally-recorded television or music programming. In an exemplary application, such programming may be transmitted via the coaxial cables that run through the walls of a home from a primary set-top box (which may be a full service set top box having a digital television receiver, DVR and/or video-on-demand capabilities, etc.) to less capable, less expensive auxiliary set-top boxes that are installed on other televisions throughout the premises. In this manner, the full capabilities of the primary set top box may be enjoyed at all of the televisions within the residence without having to provide a primary set top box for each television.
A number of MoCA-enabled signal amplifiers have been proposed. Examples of these signal amplifiers are disclosed in U.S. Pat. Nos. 8,397,271, 8,286,209, U.S. Patent Publication No. 2010/0125877, U.S. Patent Publication No. 2010/0146564 and U.S. Pat. No. 8,356,322.